Crop dusting equipment for aircraft



Jan. 30, 1951 Filed Feb. 11, 1948 c. M. DENLINGER 2,539,816

CROP DUSTINGEQUIPMENT FOR AIRCRAFT 2 Sheets-Sheet l FIG.II

mvsm'oie CARL M. DENLINGER BY mama wmflm AT ORN EYS Jan. 30, 1951 v c.M. DENLINGER 2,539,816

CROP DUSTING EQUIPMENT FOR AIRCRAFT Filed Feb. 11, 1948 2 ShecsSheet 2INVENTOR CARL M. DENLINGER ATTOR N E VS Patented Jan. 30, 1951 111E D STATE S PATENT OFFIC E gCROP DUSTING EQUIPMENT FORLAIRCRAFI Carl M;.Denlinger, DaytomOhio ,Application February 11, 1948, Serial No. 7,537

13 Claims. "1

,The present invention" has to "do with crop ;dusting equipment and is.concerned. primarily .with. such equipment that is used, in conjunctionWith aircraft.

Atjshe present time, th practice of employing v.aircraft' to dust cropswith an insecticideis becoming more and more Widespread. In accord-"ance with thisppresent day practice; the equipment'which is used'forthis purpose is perma- I nently" attached tothe aircraft orgstating itin another way, the aircraft is designed" and constructed with this solepurpose in mind.

As a practical matter; a crop dusting aircraft is only used for twoor'three months during the lcourse'of' a-year with the result that it isleft "standing-idle for the larger part of the remaining time. Thismeans that the capital investment ;;represented by the-"cost-oftheaircraft is used only a-small portion of the'time during the year.

With the foregoing condition in mind,"the

" present invention has in-view as its foremost 0b- -je'ctive theprovisionof crop dustingequipment which -isessentially auxiliary incharacter and which may lbe attached'to an aircraft when itis to be usedand removed therefrom when its use is not required, thereby leavingtheaircraft free -for other-purposes.

In -carrying out'this idea=in a-practical embodiment; it is =e'vident'that the crop "dusting equipment must: beid'etachable' from "theaircraft. :Thus, a further object'of' the'invention' is the provisionofcrop dusting equipment of 'ithetype indicated vwhichincludes means:for detachably r 'securingrthesameto an aircraft.

TDiiringthe flyingrcfan aircraft thereare a itim'esswhen'dangerouswconditions" develop and 'it 1 J becomes inecessary to drop allequipment that I! interferes zswith :the' flying operation. -With this ithought :in mind,-:,another obj ect', of the invention ..-is the-provision of :rmechanism for detachably .qsecuring: cropdusting-equipment to an aircraft .=and which mechanism includesanemergency yreleasedthat may be.operatedsbythe pilot of the,aireraft-while gin-fiight -to-get ridof the crop -..dusting equipment.Insa practical embodiment,

mechanism comparable to. the --W811+ kl1OWIl" bomb frackscgis employed;-tomount the: crop." dusting equipmentonthe .,aircraft. .rSuchaa-rbombirack includes .the emergency release required. I

.i stillvanotherr objects of V the, invention is' th -provis ion.of.crop, dusting. equipment. of the type ai0resaid.whichoiucludesflas acharacteristic element a novelcontainer for'theyinsecticide. in dustform and which container .has characteristics "which lprovide'forthe,dischar e of'its contents at l the volition of, the pilot of theaircraft. Z11 the.v

first ,p1ace, the container is, streamlined. Q'Ihis adapts-it tothe"flyingw; operationwithout materially increasing air resistance and atthe same time provides for thercreation-of; a slipstream whichentersuntoi the discharge" operationand 'will be'later' described.

The container also carries whatmight be called an inverted keerwhich ispositioned'on'the top thereof, slightly forward of the center line.*This keel cooperates with *the'bomb rack attachment 'i11 mounting thecontaineron the underside of the aircraft-wing.

"A' further object of the invention is the provision in crop dustingequipment of the-character-noted of a-streamlined containerjthe forwardpart of which is rigid with the rear part flexible.

The slip stream created by flight of the aircraft cooperates with'this'flexible rear part to cause a shakingor agitation" thereof so as toinsure discharge of its contents. This construction may be achieved byemploying aspider-like frame at the nose andusing a fabricenvelopeyvhich' covers thisframeand defines the rear part.

corollary to this object,- a" further objective is the provision ofmeansunder the c0'ntr01of thepi10t 'ofthe aircraft for operating-saiddischarge valve.

Variousother more *detailed' objects and advantages of-theinvention'such as arisein connection with carrying outtheabove=notedaideas in: apractical embodiment-will impart become description 0f :the inventionproceeds.

' The invention therefore comprisescrop-dust- --ing :equipmentzwhich 'isdesigned for detachable aconnection to anwaircraftgby connecting'meanswrearrpartewith a-discharge valve located at, the

- tail.

Forea full and more-complete understanding-of the inventionreference-maybe had to the following: description-and accompanyingdrawings wherein:

Figure 1 is. a perspeetive illustration oflanv aircraft in flight.andhaving cropv dusting equipment ,attached thereto in.a ccordance withthelprecepts ,of thisinvention.

Figure 2 is a. se tiongthrough one ,wine. oflthe aircraft along,,jtheline of one .Offlthd stream- 55,.lined containers,

Figure 3 is an end view of the tail of the container looking in from theright side of Figure 2.

Figure 4 is an enlarged detailed section taken normal to the showing ofFigure3 and about on the plane represented by the line 4- of Figure 3.

Figure 5 is a view in side elevation of the assembly at the tail of thecontainer.

Figure 6 is a view similar to Figure 5 but taken from the opposite sideof the tail.

Figure '7 is a detailed representation, partly in section and partly inelevation, showing the tail support when released.

Figure 8 is a detailed sectional view, indicated by line 8-8 on Figure9, looking in the direction of the longitudinal axis of the containerand depicts the connection between the container and the aircraft.

Figure 9 is an enlarged detailed section taken on the plane representedby the line 99 of Figure 8.

Figure 10 is a wiring diagram representing the circuits for operatingthe emergency release and opening the discharge valve.

Figure 11 is a view looking in at the stop pins associated with thereleasable hooks, and is indicated by the line H-l I on Figure 9.

Referring now to the drawings wherein like reference characters denotecorresponding parts and first more particularly to Figure 1, an aircraftis therein depicted and referred to generally by the reference characterA. It will be understood that the aircraft A may be any aircraft that isconvenient and adapted to have the equipment to be later describedattached thereto. However, it is noted that the equipment isparticularly designed for use with aircraft of the lighter type as theycruise at the lower speeds which adapts them to this use. A Piper Cub isa good example of an aircraft which may be employed.

The aircraft A includes a fuselage In which houses the seat for thepilot. The fuselage I is sus ended from wings H and the latter arebraced by the support shown at l2. In accordance with the presentinvention it is believed that the crop dusting container should bedetachably secured to the underface of the wings substantially at thepoints where the supports I2 meet the wings. As shown in Figure 1, apair of streamlined containers C and C1 are mounted on the underside ofthe wings at the points in-- dicated. Inasmuch as these containers aresubstantial duplicates only one of them is here described for thepurposes of this specification.

Referring now more particularly to Figure 2, the container C is shownasbeing of a generally streamlined formation. This container C comprises aflexible envelope l3 which preferably will be made of fabric having aweave sufficiently close to prevent the dust which the container C is tocontain from sifting therethrough or it may be made from a fabric whichhas been treated with a sizing or other substance to render it dustimpervious. A spider-like frame-work It is carried in the forward end ofthe container C and the envelope l3 fits snugly thereover, therebyproviding what is in effect a rigid forward part. I A nose shown at E issecured to the frame-work I4. The latter also has connected thereto aplate member !5 which carries a pair of loops I! in spaced relation.These loops are for the purpose of detachably securing the container 0to the aircraft A as will be later described in detail.

Rearwardly of the plate Hi the container C is formed with an openingthat is normally closed by plug l8. The purpose for this plug I8 is toprovide for the filling of the container with the insecticide in dustform which is to be discharged therefrom.

The rear part of the container C is defined by the envelope l3 alone.This rear part gradually diminishes in cross sectional area toward thetail and at the tail takes the form of a substantially cylindrical tubedesignated I9. This tube !9 carries a discharge valve in the form of arubber disc 20 that carries a sleeve 2| which snugly fits within theenvelope at LG and an external head 22 which overlies the end of thetail [9. The disc 29 is formed with a vertical slit 23 which normally isclosed due to the natural resiliency and elastic properties of therubber from which the disc 20 is made. However, when the disc 29 isdeformed in a manner to be later described, the slit 23 assumes an openposition such as represented by the dotted lines of Figure 3. It isthrough this open slit that the contents of the container C aredischarged.

Referring now more particularly to Figures 8 and 9, the wing I is shownas carrying a fairly substantial plate or structural element 24 on theinside of its lower face. The fabric covering for the wing is shown at25 as extending over the outer face of the plate 24. A bracket 25 ispermanently secured to the under face of the wing l l by bolt and nutassemblies 21. The bracket 26 carries a pair of downwardly extendingflanges 28 and 29 that are spaced apart. A flat, hollow casing 30 isformed with ears 3| which are positioned between the flanges 28 and 29.These flanges, as well as the ears 3|, are formed with aligned openingsthrough which extend shackle bolts 32 that are headed at one end andcarry a retaining device such as a cotter pin or lock ring 33 at theother end. These shackle bolts are removable so as to provide for theattaching and disattachment of the casing 30 to the bracket 26 asoccasion demands.

Pivotally mounted between the opposite fiat walls of the casing 38 are apair of hook members 31 which extend through the bottom of the casing 30and engage the closed loops [1. A rod 36 is reciprocable in casing 30 asin blocks 35a and engages hooks 31 as shown. It is evident that shiftingof the rod 36 in a right-hand direction. speaking with reference to theshowing of Figure 9, will cause the hooks 31 to be withdrawn from theloops I1. Such a shifting may be caused by a lever 38 which is pivotallyconnected as shown at 39 to the rod 36. This lever passes through anopenin in the top wall of the casing 30 and which opening constitutes afulcrum for the lever 38. This lever is disposed between the fianges 28and 29 and is adapted to be engaged by a plunger 40 of a solenoid 4|.When the solenoid 4| is energized the plunger 40 moves the lever 38 in acounterclockwise direction thereby shifting the rod 36 to the right towithdraw the hooks 31 from the loops l1 and release the container. It istherefore evident that should an emergency condition arise the pilotwill be able to energize this solenoid 4! and thereby release thecontainers C and C1. Obviously, the circuit of the solenoid M willextend to a point conveniently accessible to the pilot and a controlswitch shown at 43 will be located thereat. To prevent the loops I! fromslipping off the hooks 31 there may be provided the stop pins 31a asshown in Figures 9 and 12. A spring 36b may be employed for normallyurging the rod' 36 and hooks 31 into their Figure 9 position.

Referring now more particularly to Figures 2 to '7 inclusive, thestructure for supporting the tail of the container and opening the slit23 will now be described. An arm has its upper end anchored to theunderside of the wing i I by the plate and bolts shown at 62. The lowerend of this arm has permanently secured thereto one half of a supportinring, this half being designated $6. One end of the ring half 46 carriesa pivot pin 4? on which is mounted a complemental ring half 48. The endsof the halves 46 and 48 remote from the pivot 4'! are formed withcomplemental elements of a detachable connection. Thus, upon referringto Figure 7, it will be noted that the free end of the ring half 43 hasa recess as that is adapted. to receive a spring biased hook 5%]. has abill adapted to en age a detent 5| in the recess 49. A solenoid 52includes a plunger 53 that is adapted to engage the hook 59 when themechanism but causes the rin half 48 to swing 5 away from the ring half46 on the pivot d? and thereby release the tail is.

It will be recognized that under ordinary conditions the ring halves 46and 48 remain in the closed position illustrated. An arcuate yoke 54 iscarried by the ring half it and movement relative thereto is providedfor by the pin and slot connection shown at 55. Solenoid 56 that iscarried by the lower end of the arm 45 has a plunger 5'! that engagesthe yoke 54.

Likewise, a second arcuate yoke 58 is movably mounted on the lower ringhalf 48 and is adapted to be actuated by a plunger 59 of a solenoid Bil.

It is evident that when the solenoids 56 and 60 are energized theplungers 5'1 and 58 urge the yokes 54 and 53 into contracting relation.This deforms the rubber disc 23 so as to open the slit 23 and permitdischarge of the contents of the container.

These solenoids 5'5 and are included in the circuit of the aircraft andthe switch for energizing them which is represented at Si is located ina position conveniently accessible to the pilot. Moreover, the solenoidsfor both the containers C and C1 will probably be included in the samecircuit so that discharge valves thereof may be opened simultaneously.Of course, it would be possible, through well-known electrical circuits,to provide for the successive discharge of the contents of thecontainers C and C1.

While the mode of operation of the above described equipment is believedto be obvious, it will be noted that with any deforming forces removed,the slits 23 remain closed. Thus, a container C that is removed from theaircraft may be readily filled by removing the plug l8 and after fillingthe plu is replaced. The container 0, together with the casing 38, isnow attached to the aircraft bypositioning the ears 3! between theflanges 2B and 29 so that the openings for the shackle bolts align. Asthis is being done, the lever 38 will be passed through the slot 62. Theshackle bolts are now inserted and the cotter pins represented at 33positioned to hold the shackles in place. The operations above describedlhe latter are repeated for the container C1. At the same time, the ringhalves 48 and 48 are swung open to receive the tail i9 and then closedabout the tail with the bill of the hook 5i! engaging the detent 5| andheld in this engagement by the spring which biases the hook 5B.

The pilot now takes off and when he desires to discharge the contents ofthe containers he closes the switch M. This causes the solenoids 56 and6E] to deform the slits 23 into their open position. At this time,several elements become effective to cause the discharge of thecontents. In the first place, th slipstream created by the flight of theaircraft A afiects the flexible rear half of the containers so as toagitate and shake them and this action is further enhanced by thevibration of the aircraft. Thus, the contents are discharged through theopen slits 23.

Should an emergency condition arise and the pilot be desirous ofdropping the containers C and C1, all he has to do is close the switch43. This energizes the coils ii and 52. The coil 4| operates the bombrack and the coil 52 releases the hook 511 at the tail.

While a preferred specific embodiment of the invention is hereinbeforeset forth, it is to be clearly understood that the invention is not tobe limited to the exact constructions and mechanisms illustrated anddescribed because various modifications of these details may be providedin putting the invention into practice within the purview of theappended claims.

What is claimed is:

1. In combination, an aircraft, a container adapted to receiveinsecticide in dust form and including means for discharging saidinsecticide from the rear end of said container, mechanism fordetachably securing said container to said aircraft, and connections foroperatin said discharge means frorn said aircraft, said container beingconstructed of flexible material over a substantial portion of its areawhereby the slipstream of the aircraft assists in discharging thematerial from the container.

2. In combination, an aircraft including a wing, an element of adetachable connection on the underside of said wing, a container adaptedto receive an insecticide and including means at its rear end fordischarging said insecticide from said container, a complemental elementof said detachable connection on said container, and mechanism foroperating said discharge means from said aircraft a substantial portionof said container adjacent said means being flexible whereby theslipstream of the aircraft brings about agitation of the insecticide inthe container.

3. In combination, an aircraft including a wing, a container having arigid front part and a flexible rear part, said rear part including adischarge opening for discharging the contents of said container and avalve for controlling said opening, a detachable connection between therigid part of said container and said wing and a second detachableconnection between the flexible part of said container and said wing,and mechanism for operating said valve from within said aircraft.

4. In crop dusting equipment of the character described, a streamlinedcontainer having a nose, a rigid part contiguous to said nose, and aflexible rear part terminating in a tail, a discharge valve in saidtail, means for operatin said discharge valve, and elements of adetachable connection carried by said rigid part and tail respectively.

5. In crop dusting equipment of the character described, a streamlinedcontainer having a rigid nose part and a flexible tail part, said tailterminating in a rearwardly opening discharge opening, said containerbeing formed with an opening through which it may be filled, a removableplug closing said opening, a discharge valve in said tail forcontrolling said discharge opening, and an element of a detachableconnection carried by said container.

6. In crop dusting equipment of the character described, a streamlinedcontainer having a nose, a rigid part contiguous to said nose, and aflexible rear part terminating in a tail, said container being formedwith an opening through which it may be filled, a removable plug closingsaid opening, a discharge valve in said tail, means for operating saiddischarge valve, and elements of a detachable connection carried by saidrigid part and tail respectively.

7. In crop dusting equipment of the character described, a streamlinedcontainer includin a flexible rear part terminating in a tail, a rubberelement carried by said tail and formed with a slit, and means fordeforming said element to open said slit.

8. In crop dusting equipment of the character described, a streamlinedcontainer including a rigid front part and a flexible rear partterminating in a circular tail, a rubber disc closing said tail andformed with a slit, and means for deforming said disc to open said slit.

9. In combination, an aircraft including a wing, a streamlined containerhaving rigid and flexible parts and adapted to receive an insecticide,said container including means for discharging the contents thereof, adetachable connection between the rigid part of said container and saidaircraft wing, an emergency release included as an element of saiddetachable connection, a second detachable connection between saidflexible part and said aircraft wing, an emergency release included as apart of said second detachable connection, means for operating saidemergency releases from said aircraft, and connections for operatingsaid discharge means from said aircraft.

10. In combination, an aircraft having a wing, elements of detachableconnections secured on the under face of said wing, a streamlinedcontainer adapted to receive an insecticide and including a cylindricaldischarge spout at the rear end and a valve closing said spout,complemental elements of said detachable connections carried by saidcontainer and adapted to cooperate with the first said elements insecuring said container to said wing, emergency release means includedin said detachable connection, and means operable remotely from saidcontainer for selectively actuating said discharge valve or saidemergency release means.

11. In combination, an aircraft having a wing, an element of adetachable connection secured on the under face of said wing, acontainer adapted to receive an insecticide and including a cylindricalrear part having a discharge valve, a complemental element of saiddetachable connection carried by said container and adapted to cooperatewith the first said element in securing said container to said wing, anemergency release included in said complemental element of saiddetachable connection, and connections for operating said dischargevalve and said emergency release from said aircraft.

12. In crop dusting equipment of the character described, a containerfor insecticide, said container having a tail closed by an elasticmember formed with a slit, means for deforming said slit comprising apair of yokes engaging said element substantially opposite to the endsof the said slit, and means for urging said yokes into contractingrelation.

13. In crop dusting equipment of the character described, a containerfor insecticide, said container having a tail closed by an elasticmember formed with a slit, means for deforming said slit comprising apair of yokes engaging said element I substantially opposite to the endsof the said slit, and means for urging said yokes into contractingrelation comprising a pair of solenoids each having a plunger engagingone of said yokes.

CARL M. DENLINGER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

